US4521358A - Process for the production of silicon nitride sintered bodies - Google Patents
Process for the production of silicon nitride sintered bodies Download PDFInfo
- Publication number
- US4521358A US4521358A US06/521,283 US52128383A US4521358A US 4521358 A US4521358 A US 4521358A US 52128383 A US52128383 A US 52128383A US 4521358 A US4521358 A US 4521358A
- Authority
- US
- United States
- Prior art keywords
- weight
- parts
- chromium
- silicon nitride
- oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
- C04B35/584—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon nitride
- C04B35/593—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon nitride obtained by pressure sintering
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
- C04B35/584—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon nitride
- C04B35/591—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon nitride obtained by reaction sintering
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B3/00—Engines characterised by air compression and subsequent fuel addition
- F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
Definitions
- the present invention relates to a process for producing silicon nitride sintered bodies which have a high mechanical strength, are superior in oxidation resistance, and are of high density.
- Silicon nitride (Si 3 N 4 ) sintered bodies are superior in various characteristics such as mechanical strength, heat resistance and corrosion resistance and thus can be used as high temperature structural material, e.g., in the production of gas turbine parts.
- various sintering aids are commonly added to accelerate the sintering process because the sinterabilities of silicon nitride itself are very poor.
- silicon nitride sintered bodies are produced by a reaction sintering method, a small amount of oxide layer on the surface of metallic silicon powder inhibits a nitriding reaction.
- metals of the iron family have been added as sintering aids to accelerate the nitridation or to allow the nitriding reaction to proceed smoothly.
- Iron is effective in removing the oxide layer on the surface of metallic silicon powder. Moreover, it acts as a useful nitriding accelerator; i.e., at temperatures above 1,200° C., it reaches with metallic silicon to form a liquid phase FeSi 2 , thereby accelerating the nitriding reaction.
- the silicon nitride formed is mainly the ⁇ -phase type which is formed by the action of the liquid phase of FeSi 2 .
- the ⁇ -phase content of the final sintered body is as low as about 50% by weight.
- the strength of the silicon nitride sintered body increases with an increase in the ⁇ -phase content.
- iron as a nitriding accelerator is not preferred.
- Sintering aids added usually remain in the grain boundary phase of sintered bodies.
- the properties of the oxide layer resulting from oxidation of the sintered bodies greatly vary with the type of sintering aid.
- magnesium oxide When magnesium oxide is used as a sintering aid, the diffusion of magnesium ions from a base material to an oxide layer is a rate-determining stage. In this case, the rapid diffusion of oxygen through the oxide layer and the pores formed by release of the oxidation product, nitrogen gas, from the sample leads to more increase the weight gain after oxidation and more degradation in strength after oxidation as compared with the case in which yttrium oxide is used as a sintering aid.
- the nitriding-accelerating mechanism or oxidation mechanism varies with the type of the sintering aid used. It is also greatly influenced by the amount of the sintering aid. Hence, various attempts have been made to remove an oxide layer formed by oxidation and to improve the characteristics of the oxide layer by changing the type and amount of the sintering aid. Nevertheless, sintered bodies having satisfactory performance have not yet been produced.
- a silicon nitride sintered body produced by adding a certain oxide component as a sintering aid in combination with a chromium component to metallic silicon in the respective predetermined amounts, reaction sintering the mixture, and then again sintering the thus-prepared reaction sintered body for the purpose of further densification thereof is superior in oxidation resistance and moreover has high density and high mechanical strength, and thus is more suitable as a heat-resistant high temperature member.
- a process for producing a silicon nitride reaction sintered body which comprises molding a mixed powder comprising metallic silicon having a maximum particle size of 20 ⁇ m or less and a chromium component, the amount of the chromium component being from 0.2 to 2 parts by weight (calculated as chromium oxide) per 100 parts by weight of the metallic silicon, and reaction sintering the mold in a nitrogen gas or in a non-oxidizing atmosphere containing nitrogen gas at a temperature of from 1,300° to 1,500° C.; and
- a process for producing a silicon nitride sintered body which comprises adding from 10 to 20 parts by weight of an oxide component consisting of one or more of the oxides of yttrium, lanthanum, cerium, gadolinium, and erbium and from 0.2 to 1 part by weight (calculated as chromium oxide) of a chromium component to 100 parts by weight of metallic silicon having a maximum particle size of 20 ⁇ m or less, reaction sintering the mixture in nitrogen or in a non-oxidizing atmosphere containing nitrogen at a temperature of from 1,300° to 1,500° C. and hot-pressing the reaction sintered body.
- FIG. 1 is a graph showing the relation between a reaction sintering temperature (°C) and a degree of nitridation (%);
- FIG. 2 is a graph showing the relation between a reaction sintering temperature (°C) and an ⁇ -content (%).
- the amount of the chromium component being added is from 0.2 to 2 parts by weight (calculated as chromium oxide) per 100 parts by weight of the metallic silicon.
- the amount of the chromium component being added is from 0.5 to 2 parts by weight (calculated as chromium oxide) per 100 parts by weight of the metallic silicon.
- the chromium content of the final silicon nitride after the reaction sintering process is from 0.3 to 1.2% by weight based on the total weight of the silicon nitride sintered bodies.
- the chromium component contributes greatly to the improvement in oxidation resistance of the final silicon nitride sintered body.
- the amount of the chromium component being added is 0.2 part by weight (calculated as chromium oxide) per 100 parts by weight of the metallic silicon, the effect on acceleration of the nitridation can be obtained. This effect, however, is obtained to a lesser degree when the amount of the chromium component being added is less than 0.5 part by weight (calculated as chromium oxide) per 100 parts by weight of the metallic silicon; i.e., the chromium content of the final silicon nitride sintered body is less than 0.3% by weight.
- the amount of the chromium component being added is more than 2 parts by weight (caluculated as chromium oxide) per 100 parts by weight of the metallic silicon; i.e., the chromium content of the final silicon nitride sintered body is more than 1.2% by weight, the effect of acceleration of nitridation can be obtained, but the strength of the reaction sintered body tends to drop.
- the maximum particle size of the metallic silicon powder must be 20 ⁇ m or less. If the maximum particle size is more than 20 ⁇ m, unreacted metallic silicon remains even if the chromium component is added. In connection with the chromium component, it is preferred for the maximum particle size to be 20 ⁇ m or less. If the particle size of the chromium component exceeds 20 ⁇ m, it is not possible to disperse the chromium component uniformly, and the effect of adding the chromium component is reduced.
- the chromium component is added to the metallic silicon in a proportion of from 0.2 to 2 parts by weight (calculated as chromiun oxide) per 100 parts by weight of the metallic silicon.
- the resulting mixture is then ground in a ball mill, for example, and molded in a desired form. Then the mold thus prepared is reaction sintered.
- reaction sintering process it is necessary for the reaction sintering process to be performed in a nitrogen gas or in a non-oxidizing atmosphere of a mixed gas of nitrogen and ammonia, inert gas, hydrogen or the like at a temperature of from 1,300° to 1,500° C., more preferably from 1,350° to 1,450° C. If the temperature is lower than 1,350° C., unreacted metallic silicon remains, whereas if it is higher than 1,450° C., the ⁇ -phase content of the silicon nitride formed tends to increase.
- the chromium component crystallizes glassy SiO 2 on the surface of metallic silicon powder, causing cracks to be formed in the SiO 2 layer and thus allowing SiO 2 gas, a reaction product of metallic silicon and SiO 2 , to escape through the cracks. Once this reaction occurs, it continues to proceed until the SiO 2 is completely consumed, while causing the formation of cracks. As a result, the surface of the metallic silicon is maintained in a very clean condition and the nitriding reaction occurs easily on the surface. Moreover, the chromium component does not easily form a liquid phase on reacting with metallic silicon. In this case, therefore, the formation of ⁇ -Si 3 N 4 is prevented compared with the case in which iron is added.
- the metallic silicon an oxide component of one or more of the oxides of yttrium, lanthanum, cerium, gadolinium, and erbium, a chromium component exemplified by chromium oxide, and a nitrogen gas component are used.
- the oxide component and the chromium component are used in combination as a sintering aid, producing the synergistic effect that both the oxidation resistance and mechanical strength are greatly increased.
- the oxide component excluding the chromium component acts as a sintering aid at the time of hot pressing. It is necessary for the oxide component to be added in an amount of from 10 to 20 parts by weight per 100 parts by weight of the metallic silicon. If the amount of the oxide component exceeds the upper limit, the mechanical strength is low and the oxidation resistance is poor, although the density is good. On the other hand, if it is below the lower limit, the density is inferior and the mechanical strength lowers.
- the chromium component is considered to have, in addition to the effect of acceleration of nitriding as described above, the following effect:
- the chromium component accelerates crystallization of the oxide of yttrium, lanthanum, cerium, gadolinium or erbium and the glass-like compound of silicon dioxide, resulting from oxidation of the hot pressed body, and prevents the formation of cracks in the oxide layer of the hot pressed body, thereby increasing the oxidation resistance.
- the amount of the chromium component being added is less than 0.2 part by weight (calculated as chromium oxide)
- the effect of acceleration of nitridation is decreased, and moreover, the crystallization of the oxide of yttrium, lanthanum, cerium, gadolinium, and erbium and the glass-like compound of silicon dioxide is reduced.
- the effects of acceleration of nitridation and of crsytallization are hardly increased or remain unchanged even if the chromium component is added in greater amounts.
- the amount of the chromium component being added is too large, the mechanical strength of the hot press sintered body falls. Therefore, when the hot pressing is used in combination, is preferably the amount of the chromium component being added up to 1 part by weight (calculated as chromium oxide).
- metallic silicon powder (and not silicon nitride) is used as a starting material, and the metallic silicon powder is subjected to a nitriding treatment.
- the reasons for this are as follows: (1) Silicon nitride particles formed by the nitriding treatment are superior in sintering properties since they are finer than silicon nitride particles commercially available, and moreover, their grain sizes are relatively uniform. (2) Oxygen always exists on the surface of silicon nitride powder, and the amount of oxygen contained in the silicon nitride formed by subjecting metallic silicon to the nitriding treatment is much less than that of the oxygen existing on the surface of silicon nitride powder. As a result, the properties of the grain boundary phase of the sintered body are superior to those in the case where silicon nitride powder is used as a starting material.
- the metallic silicon powder as used herein must have a maximum particle size of 20 ⁇ m or less even when hot pressing is used in combination. If the maximum particle size is more than 20 ⁇ m, unreacted metallic silicon remains even if chromium oxide to accelerate the nitriding reaction is added at the nitriding treatment. The unreacted metallic silicon is responsible for defects in the sintered body obtained by performing the hot pressing.
- the oxide component of one or more of the oxides of yttrium, lanthanum, cerium, gadolinium, and erbium, which has been finely ground is added as a sintering aid to metallic silicon in an amount of from 10 to 20 parts by weight per 100 parts by weight of the metallic silicon, and also, the chromium component which has been finely ground is added in an amount (calculated as chromium oxide) of from 0.2 to 1 part by weight per 100 parts by weight of the metallic silicon.
- the resulting mixture is ground in a ball mill, for example, and when molded, is molded in a desired from by application of a pressure of from about 2,000 to 5,000 kg/cm 2 .
- the mold is then reaction sintered in a non-oxidizing atmosphere of nitrogen gas or a mixed gas of nitrogen and ammonia, inert gas, hydrogen or the like at a temperature of from 1,300° to 1,500° C., preferably from 1,350° to 1,450° C. and, thereafter, is subjected to hot pressing.
- This hot pressing is sufficient if performed under the conditions of temperature of from 1,600° to 1,900° C., pressure of from 100 to 500 kg/cm 2 (preferably from 200 to 400 kg/cm 2 ), and in a non-oxidizing atmosphere, such as a reducing atmosphere and a neutral atmosphere.
- the embodiment (2) is more preferred.
- the chromium component or a mixture of the chromium component and the oxide component is added as a sintering aid to metallic silicon in a specific amount to produce the desired sintered body.
- the thus-produced sintered body is superior in oxidation resistance and moreover is of high density and has a high mechanical strength because of its novel composition.
- the sintered body is suitable for use as, e.g., gas turbine parts or diesel parts, for which heat resistance and oxidation resistance are required.
- FIGS. 1 and 2 The characteristics of each reaction sintered body are shown in FIGS. 1 and 2.
- FIG. 1 shows the relation between the reaction sintering temperature and the degree of nitridation.
- the degree of nitridation was calculated by the following equation: ##EQU1##
- FIG. 2 shows the relation between the reaction sintering temperature and the ⁇ -content.
- the ⁇ -content was calculated from the following equation: ##EQU2## (wherein I ⁇ is a mean peak intensity of (102) and (210) of X-ray diffraction peaks of 60 -Si 3 N 4 , and I ⁇ is a mean peak intensity of (101) and (210) of X-ray diffraction peaks of ⁇ -Si 3 N 4 .
- x 1 , x 2 amount of sintering aid added
- dSi 3 N 4 theoretical density of silicon nitride (g/cm 2 ),
- dx 1 , dx 2 density of sintering aid (g/cm 3 )).
- Comparative samples were prepared in which the chromium component was not added, or the type of the oxide component was changed to those different from the oxides of the invention, and were tested in the same manner as above. The results are shown in Table 2.
- Run Nos. 1 to 3 comparative examples in which chromium oxide is not used in combination although yttrium oxide (Y 2 O 3 ) is used as in Run No. 7, the increase of amount due to oxidation is very large compared with that in Run No. 7. Also, the theoretical density ratio indicating the density of material is unsatisfactorily low in Run No. 1.
- Run Nos. 7 to 11 examples of the invention in which yttrium oxide, lanthanum oxide (La 2 O 3 ), cerium oxide (CeO 2 ), gadolinium oxide (Gd 2 O 3 ) and erbium oxide (Er 2 O 3 ) are added each in an amount of 16 parts by weight
- Run Nos. 4 to 6 in which equal amounts of praseodymium oxide (Pr 6 O 11 ), neodymium oxide (Nd 2 O 3 ) and dysprosium oxide (Dy 2 O 3 ) are used are large in the weight gain of samples after oxidation.
- Dy 2 O 3 when Dy 2 O 3 is used, the theoretical density ratio is very low and the weight gain of samples after oxidation is very large.
Abstract
Description
TABLE 1 ______________________________________ Metallic Silicon Chromium Oxide Run No. (parts by weight) (parts by weight) ______________________________________ 1 (Comparative 100 0 Example) 2 (Example of the 100 0.5 Invention) 3 (Example of the 100 1 Invention) 4 (Example of the 100 2 Invention) ______________________________________
TABLE 2 ______________________________________ Evaluation Theo- Weight Gain Composition (parts by weight) retical of Samples Run Metallic Chromi- Density after No. Silicon Oxide um Oxide Ratio Oxidation ______________________________________ 1 100 Y.sub.2 O.sub.3 8 0 96.4 0.25 2 100 Y.sub.2 O.sub.3 16 0 100 0.36 3 100 Y.sub.2 O.sub.3 24 0 100 0.41 4 100 Pr.sub.6 O.sub.11 16 0.5 99.8 0.35 5 100 Nd.sub.2 O.sub.3 16 0.5 99.6 0.63 6 100 Dy.sub.2 O.sub.3 16 0.5 92.6 0.96 7 100 Y.sub.2 O.sub.3 16 0.5 99.5 0.19 8 100 La.sub.2 O.sub.3 16 0.5 99.9 0.33 9 100 CeO.sub.2 16 0.5 99.1 0.24 10 100 Gd.sub.2 O.sub.3 16 0.5 99.1 0.27 11 100 Er.sub.2 O.sub.3 16 0.5 96.9 0.25 ______________________________________ Note: Run Nos. 1 to 6 are comparative examples, and Run Nos. 7 to 11 are examples of the invention.
Claims (7)
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57-139149 | 1982-08-12 | ||
JP57139149A JPS5934677B2 (en) | 1982-08-12 | 1982-08-12 | Method for manufacturing silicon nitride reaction sintered body |
JP57-139150 | 1982-08-12 | ||
JP57139150A JPS5934678B2 (en) | 1982-08-12 | 1982-08-12 | Method for producing highly corrosion-resistant chambered silicon sintered body |
Publications (1)
Publication Number | Publication Date |
---|---|
US4521358A true US4521358A (en) | 1985-06-04 |
Family
ID=26472047
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US06/521,283 Expired - Lifetime US4521358A (en) | 1982-08-12 | 1983-08-08 | Process for the production of silicon nitride sintered bodies |
Country Status (1)
Country | Link |
---|---|
US (1) | US4521358A (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4921657A (en) * | 1987-11-13 | 1990-05-01 | Dow Corning Corporation | Method for densification of amorphous ceramic material |
US5055432A (en) * | 1990-07-24 | 1991-10-08 | Eaton Corporation | Process for preparing a nitridable silicon-containing material having at least one densification aid including alumina, and the material resulting therefrom |
US5079198A (en) * | 1990-07-24 | 1992-01-07 | Eaton Corporation | Ceramic phase in sintered silicon nitride containing cerium, aluminum, and iron |
US5275985A (en) * | 1987-10-22 | 1994-01-04 | Cooper Industries, Inc. | Production of a sintered reaction bonded silicon nitride insulator |
US5348919A (en) * | 1992-07-14 | 1994-09-20 | Shin-Etsu Chemical Co., Ltd. | High-packing silicon nitride powder and method for making |
US5382554A (en) * | 1991-03-18 | 1995-01-17 | Shin-Etsu Chemical Co., Ltd. | High-packing silicon nitride powder and method for making |
US6197243B1 (en) | 1993-04-16 | 2001-03-06 | Ut Battelle, Llc | Heat distribution ceramic processing method |
US20060071374A1 (en) * | 2004-10-05 | 2006-04-06 | Asahi Glass Company, Limited | Method for producing silicon nitride filter |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4004937A (en) * | 1972-10-24 | 1977-01-25 | Kabushiki Kaisha Toyota Chuo Kenkyusho | Method for producing a sintered silicon nitride base ceramic and said ceramic |
US4097293A (en) * | 1969-04-30 | 1978-06-27 | Tokyo Shibaura Electric Co., Ltd. | Method for manufacturing heat-resistant reinforced composite materials |
US4280850A (en) * | 1978-06-15 | 1981-07-28 | Gte Laboratories, Incorporated | S13N4 Having high temperature strength and method |
US4332909A (en) * | 1979-11-22 | 1982-06-01 | Tokyo Shibaura Denki Kabushiki Kaisha | Silicon nitride based sintered product and method of producing the same |
US4440707A (en) * | 1981-09-30 | 1984-04-03 | Ngk Spark Plug Co., Ltd. | Process for producing silicon nitride sintered products having high toughness |
-
1983
- 1983-08-08 US US06/521,283 patent/US4521358A/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4097293A (en) * | 1969-04-30 | 1978-06-27 | Tokyo Shibaura Electric Co., Ltd. | Method for manufacturing heat-resistant reinforced composite materials |
US4004937A (en) * | 1972-10-24 | 1977-01-25 | Kabushiki Kaisha Toyota Chuo Kenkyusho | Method for producing a sintered silicon nitride base ceramic and said ceramic |
US4280850A (en) * | 1978-06-15 | 1981-07-28 | Gte Laboratories, Incorporated | S13N4 Having high temperature strength and method |
US4332909A (en) * | 1979-11-22 | 1982-06-01 | Tokyo Shibaura Denki Kabushiki Kaisha | Silicon nitride based sintered product and method of producing the same |
US4440707A (en) * | 1981-09-30 | 1984-04-03 | Ngk Spark Plug Co., Ltd. | Process for producing silicon nitride sintered products having high toughness |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5275985A (en) * | 1987-10-22 | 1994-01-04 | Cooper Industries, Inc. | Production of a sintered reaction bonded silicon nitride insulator |
US4921657A (en) * | 1987-11-13 | 1990-05-01 | Dow Corning Corporation | Method for densification of amorphous ceramic material |
US5055432A (en) * | 1990-07-24 | 1991-10-08 | Eaton Corporation | Process for preparing a nitridable silicon-containing material having at least one densification aid including alumina, and the material resulting therefrom |
US5079198A (en) * | 1990-07-24 | 1992-01-07 | Eaton Corporation | Ceramic phase in sintered silicon nitride containing cerium, aluminum, and iron |
WO1992001651A1 (en) * | 1990-07-24 | 1992-02-06 | Eaton Corporation | Process for making nitridable silicon material |
WO1992001647A1 (en) * | 1990-07-24 | 1992-02-06 | Eaton Corporation | Ceramic phase in silicon nitride containing cerium |
US5382554A (en) * | 1991-03-18 | 1995-01-17 | Shin-Etsu Chemical Co., Ltd. | High-packing silicon nitride powder and method for making |
US5348919A (en) * | 1992-07-14 | 1994-09-20 | Shin-Etsu Chemical Co., Ltd. | High-packing silicon nitride powder and method for making |
US6197243B1 (en) | 1993-04-16 | 2001-03-06 | Ut Battelle, Llc | Heat distribution ceramic processing method |
US20060071374A1 (en) * | 2004-10-05 | 2006-04-06 | Asahi Glass Company, Limited | Method for producing silicon nitride filter |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4285895A (en) | Method of densifying a reaction bonded silicon nitride article | |
US6284690B1 (en) | Si3N4 ceramic, Si-base composition for production thereof and processes for producing these | |
US4143107A (en) | Silicon nitride-based sintered material and method for manufacturing the same | |
US4511402A (en) | Sintered silicon nitride products and processes for fabrication thereof | |
US4046580A (en) | Silicon nitride-based sintered material and method for manufacturing the same | |
EP0626358A2 (en) | Electrically conductive high strength dense ceramic | |
US4134947A (en) | Sintered silicon nitride body and a method of producing the same | |
US4218257A (en) | Sintered silicon nitride body and a method of producing the same | |
US4376742A (en) | Fugitive liquid phase densification of silicon nitride | |
US4521358A (en) | Process for the production of silicon nitride sintered bodies | |
US4716133A (en) | Method for production of silicon nitride sintered body | |
EP0540642B1 (en) | Preparing alpha-phase silicon nitride, converting to beta-phase | |
US3572992A (en) | Preparation of moulded and sintered aluminum nitride | |
EP0540671B1 (en) | Preparing silicon nitride with densification aid, and results | |
US5126294A (en) | Sintered silicon nitride and production method thereof | |
US5055432A (en) | Process for preparing a nitridable silicon-containing material having at least one densification aid including alumina, and the material resulting therefrom | |
US5166106A (en) | Silicon-containing material having at least one densification aid including alumina | |
EP0676380A1 (en) | Composite powders of silicon nitride and silicon carbide | |
JPH0336782B2 (en) | ||
US4810678A (en) | Gas pressure sintering of silicon nitride with addition of rare earth oxides | |
JP2649220B2 (en) | Silicon nitride / silicon carbide composite powder, composite compact, method for producing them, and method for producing silicon nitride / silicon carbide composite sintered body | |
US5545362A (en) | Production method of sintered silicon nitride | |
JPS62252374A (en) | Manufacture of aluminum nitride sintered body | |
JP2826080B2 (en) | Silicon nitride / silicon carbide composite sintered body and method for producing composite powder | |
JPH03174364A (en) | Silicon nitride-based sintered body |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: AGENCY OF INDUSTRIAL SCIENCE & TECHNOLOGY, NO. 3-1 Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:MIURA, KAZUNORI;HATTORI, YOSHINORI;MATSUO, YASUSHI;REEL/FRAME:004371/0727 Effective date: 19830720 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Free format text: PAT HLDR NO LONGER CLAIMS SMALL ENT STAT AS INDIV INVENTOR (ORIGINAL EVENT CODE: LSM1); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 12 |